Page 63 - AJWEP-22-5

Performance and applications of dewatering technologies

whereas roller press (38.5%), screw press (34.4%), and balance between dewatering efficiency and operational
hydrocyclone (26.5%) show intermediate results. On feasibility. In contrast, lower-performing methods
the lower end, filter press (21.5%), screen separation may still be useful where partial moisture removal is
(22.5%), and rotating screen (18%) have the least sufficient or when energy and operational constraints
effectiveness in removing moisture, making them less limit the use of high-performance technologies. The
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suitable for applications requiring high solid content. selection of an appropriate dewatering method depends
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The comparison of total solid content with different on factors such as cost, energy consumption, and the
dewatering technologies is shown in Figure 2. specific requirements of the application. 21
The findings suggest that high-performing methods, The screw press dewatering machine effectively
such as the vibrating screen and belt press, are ideal compresses the biodigestate, allowing it to be used for
for industries needing maximum moisture removal to numerous purposes. Screw press dewatering devices
improve material handling and reduce drying costs. are also less energy-intensive, therefore lowering
Moderate-efficiency methods, such as centrifugal their operating cost over their lifetime. Since they
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separation and inclined stationary screens, offer a have fewer moving components, the maintenance
frequency is also lower. The higher initial investment
and limited capacity of the machine are the main
• Assess the performance of dewatering technologies for
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Problem bio-digestate drawbacks of the screw press machine. Based on
identification • Identify key challenges in bio-digestate management
• Investigate technological gaps in developing countries previous researches and experiments, the screw press
dewatering machine is considered the most beneficial
item to design. This machine retains higher amounts
• Review existing literature on dewatering technologies of nitrogen, phosphorus, and potassium in the solid
Literature • Analyze experimental studies on dewatering machines
review • Evaluate the performance and economic aspects of output compared to other dewatering systems. Its low
dewatering machines
energy consumption and effective solids removal make
it a viable option for both dewatering and nutrient
conservation. However, preserving nutrients may
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• Examine various dewatering methods
Dewatering
technologies • Analyze the design, process flow, and energy requirements result in lower total solid output compared to methods
of dewatering machines
such as centrifuge or belt press dewatering. Therefore,
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when choosing the right system, one should consider
• Identify technologies: screw press, belt press, centrifuge, the trade-off between maximizing nutrient retention and
Performance and thermally assisted mechanical dewatering
evaluation • Evaluate digestate characteristics: moisture content, total achieving efficient solids separation, depending on the
solids, energy consumption, and nutrient retention
specific application requirements. In practical terms,
industries that prioritize nutrient conservation, such as
those involved in agriculture or fertilizer recovery, may
Results and • Analyze performance and efficiency metrics prefer this system, even if it results in lower total solids.
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• Identify promising and efficient technologies for future
discussions
application An experiment performed in 2011 demonstrated that it
Figure 1. The systematic approach applied to the would not be possible to reduce the total solid content
current review in the liquid fraction below 40% of the total mass of the
solid–liquid mixture, as the solids would be in dissolved
form and cannot be removed by pressure filtration. 27
On the other hand, applications focused on achieving
the highest possible dewatering efficiency, such as
wastewater treatment plants, might favor technologies
such as belt press or centrifugation, which remove more
moisture but may lead to greater nutrient loss. Thus,
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the choice of technology should align with the end-use
goals, whether they are nutrient recycling, moisture
reduction, or energy saving. 29
TAMD is an advanced technique designed to
enhance the energy efficiency of liquid–solid separation
Figure 2. Comparison of various mechanical processes. This method improves the performance
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dewatering technologies based on total solid content of conventional dewatering systems by integrating

Volume 22 Issue 5 (2025) 57 doi: 10.36922/AJWEP025130093